This is a grape amethyst (sometimes referred to as grape agate) mineral specimen.

Grape amethyst is actually a kind of chalcedony, not an agate at all. It is characterized by having many quartz crystals with botryoidal (spherical) habit, which combined with the beautiful purple hue quite resemble a bunch of grapes, hence the name.

Size Approx. 3” x 1.5” x 0.5”

Mamuju area, Sulawesi Barat Prov., Sulawesi Indonesia